Stereoscopic video display technology of a glasses-less type capable of perceiving stereoscopic video without using special glasses can be classified in various ways. Such stereoscopic video display technology is generally classified into a binocular parallax method using a binocular parallax and a spatial image reproducing method that actually forms a spatial image.
The binocular parallax method is further classified into a twin type and a multi type. The twin type is a method by which an image for the left eye and an image for the right eye are made visible by the left eye and the right eye, respectively. The multi type is a method by which a range in which stereoscopic video is observable is broadened by using a plurality of observation positions when a video is shot to increase the amount of information.
The spatial image reproducing method is further classified into a holograph method and an integral photography method (hereinafter, called the integral method, but may also be called a ray reproducing method). The integral method may be classified as the binocular parallax method. According to the integral method, rays take quite opposite paths between shooting and reproducing video and thus, almost complete stereoscopic video is reproduced if the number of rays is made sufficiently large and the pixel size can be made sufficiently small. Thus, the ideal integral method is classified as the spatial image reproducing method.
Incidentally, to perceive stereoscopic video without glasses as in the multi type and the integral method, the configuration described below is normally adopted. A stereoscopic video display pixel arrangement is configured on a two-dimensional image display pixel arrangement. A mask (also called a ray control element) having a function to control rays from stereoscopic video display pixels is arranged on a front face side of the stereoscopic video display pixel arrangement. The mask is provided with window portions far smaller than stereoscopic video display pixels (typically as small as two-dimensional image display pixels) in positions corresponding to stereoscopic video display pixels.
A fly eye lens in which micro-lenses are arranged two-dimensionally, a lenticular seat in a shape in which optical openings extend linearly in the vertical direction and are periodically arranged in the horizontal direction, or slits are used as the mask.
According to such a configuration, element images displayed by individual stereoscopic video display pixels are partially blocked by the mask so that an observer visually recognizes only element images that have passed through window portions. Therefore, two-dimensional image display pixels visually recognized via some window portion can be made different from observation position to observation position so that stereoscopic video can be perceived without glasses.